import Foundation
import AsyncDisplayKit
import Display
import TelegramCore
import Postbox
import SwiftSignalKit

private enum SubscriberAction {
    case join
    case kicked
    case muteNotifications
    case unmuteNotifications
}

private func titleAndColorForAction(_ action: SubscriberAction, theme: PresentationTheme, strings: PresentationStrings) -> (String, UIColor) {
    switch action {
        case .join:
            return (strings.Channel_JoinChannel, theme.chat.inputPanel.panelControlAccentColor)
        case .kicked:
            return (strings.Channel_JoinChannel, theme.chat.inputPanel.panelControlDisabledColor)
        case .muteNotifications:
            return (strings.Conversation_Mute, theme.chat.inputPanel.panelControlAccentColor)
        case .unmuteNotifications:
            return (strings.Conversation_Unmute, theme.chat.inputPanel.panelControlAccentColor)
    }
}

private func actionForPeer(peer: Peer, isMuted: Bool) -> SubscriberAction? {
    if let channel = peer as? TelegramChannel {
        switch channel.participationStatus {
            case .kicked:
                return .kicked
            case .left:
                return .join
            case .member:
                if isMuted {
                    return .unmuteNotifications
                } else {
                    return .muteNotifications
                }
        }
    } else {
        return nil
    }
}

private let badgeFont = Font.regular(14.0)

final class ChatChannelSubscriberInputPanelNode: ChatInputPanelNode {
    private let button: UIButton
    private let discussButton: UIButton
    private let badgeBackground: ASImageNode
    private let badgeText: ImmediateTextNode
    private let activityIndicator: UIActivityIndicatorView
    
    private var action: SubscriberAction?
    
    private let actionDisposable = MetaDisposable()
    private let badgeDisposable = MetaDisposable()
    
    private var presentationInterfaceState: ChatPresentationInterfaceState?
    
    private var layoutData: (CGFloat, CGFloat, CGFloat)?
    
    override init() {
        self.button = UIButton()
        self.discussButton = UIButton()
        self.activityIndicator = UIActivityIndicatorView(activityIndicatorStyle: .gray)
        self.activityIndicator.isHidden = true
        
        self.badgeBackground = ASImageNode()
        self.badgeBackground.displaysAsynchronously = false
        self.badgeBackground.displayWithoutProcessing = true
        self.badgeBackground.isHidden = true
        
        self.badgeText = ImmediateTextNode()
        self.badgeText.displaysAsynchronously = false
        self.badgeText.isHidden = true
        
        self.discussButton.addSubnode(self.badgeBackground)
        self.discussButton.addSubnode(self.badgeText)
        
        super.init()
        
        self.view.addSubview(self.button)
        self.view.addSubview(self.discussButton)
        self.view.addSubview(self.activityIndicator)
        
        self.button.addTarget(self, action: #selector(self.buttonPressed), for: [.touchUpInside])
        self.discussButton.addTarget(self, action: #selector(self.discussPressed), for: [.touchUpInside])
    }
    
    deinit {
        self.actionDisposable.dispose()
        self.badgeDisposable.dispose()
    }
    
    override func hitTest(_ point: CGPoint, with event: UIEvent?) -> UIView? {
        return super.hitTest(point, with: event)
        
        if self.bounds.contains(point) {
            return self.button
        } else {
            return nil
        }
    }
    
    @objc func buttonPressed() {
        guard let context = self.context, let action = self.action, let presentationInterfaceState = self.presentationInterfaceState, let peer = presentationInterfaceState.renderedPeer?.peer else {
            return
        }
        
        switch action {
            case .join:
                self.activityIndicator.isHidden = false
                self.activityIndicator.startAnimating()
                self.actionDisposable.set((context.peerChannelMemberCategoriesContextsManager.addMember(account: context.account, peerId: peer.id, memberId: context.account.peerId)
                    |> afterDisposed { [weak self] in
                    Queue.mainQueue().async {
                        if let strongSelf = self {
                            strongSelf.activityIndicator.isHidden = true
                            strongSelf.activityIndicator.stopAnimating()
                        }
                    }
                }).start())
            case .kicked:
                break
            case .muteNotifications, .unmuteNotifications:
                if let context = self.context, let presentationInterfaceState = self.presentationInterfaceState, let peer = presentationInterfaceState.renderedPeer?.peer {
                    self.actionDisposable.set(togglePeerMuted(account: context.account, peerId: peer.id).start())
                }
        }
    }
    
    @objc private func discussPressed() {
        if let presentationInterfaceState = self.presentationInterfaceState, let peerDiscussionId = presentationInterfaceState.peerDiscussionId {
            self.interfaceInteraction?.navigateToChat(peerDiscussionId)
        }
    }
    
    override func updateLayout(width: CGFloat, leftInset: CGFloat, rightInset: CGFloat, maxHeight: CGFloat, transition: ContainedViewLayoutTransition, interfaceState: ChatPresentationInterfaceState, metrics: LayoutMetrics) -> CGFloat {
        self.layoutData = (width, leftInset, rightInset)
        
        if self.presentationInterfaceState != interfaceState {
            let previousState = self.presentationInterfaceState
            self.presentationInterfaceState = interfaceState
            
            if previousState?.theme !== interfaceState.theme {
                self.badgeBackground.image = PresentationResourcesChatList.badgeBackgroundActive(interfaceState.theme)
            }
            
            if previousState?.peerDiscussionId != interfaceState.peerDiscussionId {
                let signal: Signal<Int?, NoError>
                if let peerDiscussionId = interfaceState.peerDiscussionId, let context = self.context {
                    let key = PostboxViewKey.unreadCounts(items: [.peer(peerDiscussionId)])
                    let inclusionKey = PostboxViewKey.peerChatInclusion(peerDiscussionId)
                    signal = context.account.postbox.combinedView(keys: [key, inclusionKey])
                    |> map { view -> Int? in
                        guard let inclusionView = view.views[inclusionKey] as? PeerChatInclusionView, let countsView = view.views[key] as? UnreadMessageCountsView else {
                            return nil
                        }
                        if !inclusionView.inclusion {
                            return nil
                        }
                        if let count = countsView.count(for: .peer(peerDiscussionId)), count != 0 {
                            return Int(count)
                        } else {
                            return nil
                        }
                    }
                    |> distinctUntilChanged
                } else {
                    signal = .single(nil)
                }
                self.badgeDisposable.set((signal
                |> deliverOnMainQueue).start(next: { [weak self] value in
                    guard let strongSelf = self, let interfaceState = strongSelf.presentationInterfaceState, let image = strongSelf.badgeBackground.image else {
                        return
                    }
                    let text = "\(value ?? 0)"
                    
                    strongSelf.badgeText.attributedText = NSAttributedString(string: text, font: badgeFont, textColor: interfaceState.theme.chatList.unreadBadgeActiveTextColor)
                    let textSize = strongSelf.badgeText.updateLayout(CGSize(width: 100.0, height: 100.0))
                    let badgeSize = CGSize(width: max(image.size.width, textSize.width + 4.0), height: image.size.height)
                    let badgeFrame = CGRect(origin: CGPoint(x: strongSelf.discussButton.bounds.width + 5.0, y: floor((strongSelf.discussButton.bounds.height - badgeSize.height) / 2.0)), size: badgeSize)
                    strongSelf.badgeBackground.frame = badgeFrame
                    strongSelf.badgeText.frame = CGRect(origin: CGPoint(x: badgeFrame.minX + floor((badgeSize.width - textSize.width) / 2.0), y: badgeFrame.minY + floor((badgeSize.height - textSize.height) / 2.0)), size: textSize)
                    if value == nil || value == 0 {
                        strongSelf.badgeBackground.isHidden = true
                        strongSelf.badgeText.isHidden = true
                    } else {
                        strongSelf.badgeBackground.isHidden = false
                        strongSelf.badgeText.isHidden = false
                    }
                }))
            }
            
            if let peer = interfaceState.renderedPeer?.peer, previousState?.renderedPeer?.peer == nil || !peer.isEqual(previousState!.renderedPeer!.peer!) || previousState?.theme !== interfaceState.theme || previousState?.strings !== interfaceState.strings || previousState?.peerIsMuted != interfaceState.peerIsMuted || previousState?.peerDiscussionId != interfaceState.peerDiscussionId {
                if let action = actionForPeer(peer: peer, isMuted: interfaceState.peerIsMuted) {
                    self.action = action
                    let (title, color) = titleAndColorForAction(action, theme: interfaceState.theme, strings: interfaceState.strings)
                    self.button.setTitle(title, for: [])
                    self.button.setTitleColor(color, for: [.normal])
                    self.button.setTitleColor(color.withAlphaComponent(0.5), for: [.highlighted])
                    self.button.sizeToFit()
                } else {
                    self.action = nil
                }
                
                if interfaceState.peerDiscussionId != nil {
                    self.discussButton.setTitle(interfaceState.strings.Channel_DiscussionGroup_HeaderLabel, for: [])
                    self.discussButton.setTitleColor(interfaceState.theme.chat.inputPanel.panelControlAccentColor, for: [.normal])
                    self.discussButton.setTitleColor(interfaceState.theme.chat.inputPanel.panelControlAccentColor.withAlphaComponent(0.5), for: [.highlighted])
                    self.discussButton.sizeToFit()
                    self.discussButton.isHidden = false
                } else {
                    self.discussButton.isHidden = true
                }
            }
        }
        
        let panelHeight = defaultHeight(metrics: metrics)
        
        let buttonSize = self.button.bounds.size
        let discussSize = self.discussButton.bounds.size
        if self.discussButton.isHidden {
            self.button.frame = CGRect(origin: CGPoint(x: leftInset + floor((width - leftInset - rightInset - buttonSize.width) / 2.0), y: floor((panelHeight - buttonSize.height) / 2.0)), size: buttonSize)
        } else {
            let availableWidth = floor((width - leftInset - rightInset) / 2.0)
            self.button.frame = CGRect(origin: CGPoint(x: leftInset + floor((availableWidth - buttonSize.width) / 2.0), y: floor((panelHeight - buttonSize.height) / 2.0)), size: buttonSize)
            self.discussButton.frame = CGRect(origin: CGPoint(x: leftInset + availableWidth + floor((availableWidth - discussSize.width) / 2.0), y: floor((panelHeight - discussSize.height) / 2.0)), size: discussSize)
            let badgeOffset = self.discussButton.bounds.width + 5.0 - self.badgeBackground.frame.minX
            self.badgeBackground.frame = self.badgeBackground.frame.offsetBy(dx: badgeOffset, dy: 0.0)
            self.badgeText.frame = self.badgeText.frame.offsetBy(dx: badgeOffset, dy: 0.0)
        }
        
        let indicatorSize = self.activityIndicator.bounds.size
        self.activityIndicator.frame = CGRect(origin: CGPoint(x: width - rightInset - indicatorSize.width - 12.0, y: floor((panelHeight - indicatorSize.height) / 2.0)), size: indicatorSize)
        
        return panelHeight
    }
    
    override func minimalHeight(interfaceState: ChatPresentationInterfaceState, metrics: LayoutMetrics) -> CGFloat {
        return defaultHeight(metrics: metrics)
    }
}